Combined HAIC, Lenvatinib and Pucotenlimab as Conversion Therapy for Unresectable Intrahepatic Cholangiocarcinoma

Inclusion Criteria: * Histologically confirmed intrahepatic cholangiocarcinoma. * Age ≥18 years. * ECOG performance status score of 0 or 1. * Not suitable for radical surgery (including radical hepatic resection, liver transplantation or ablation) after evaluation by the MDT expert group of treating hepatobiliary cancer. Specifically, any of the following conditions are met： 1. R0 resection is not feasible. 2. in subjects without cirrhosis, the volume of normal liver parenchyma is less than 30% of the total volume, or in patients with cirrhosis, the volume of normal liver parenchyma is less than 40% of the total volume, or ICG-R15\>15%. 3. Number of lesions \>1. * No prior systemic anti-tumor treatment for intrahepatic cholangiocarcinoma before the first dose. * According to the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST V1.1), at least 1 measurable lesion, or a measurable lesion that has clearly progressed (based on RECIST V1.1 criteria) after local treatment. * Subjects with portal vein tumor thrombus (PVTT): 1. Chen's group A and B, or Cheng's type I-III can be enrolled. 2. Chen's group C, or Cheng's type IV (superior vena cava tumor thrombus) cannot be enrolled. * Subjects with hepatic vein tumor thrombus: 1. VV1 and VV2 types can be enrolled. 2. VV3 type, or Sakamoto type I (inferior vena cava tumor thrombus) can also be enrolled. 3. Sakamoto type II (inferior vena cava tumor thrombus extending above the diaphragm), or Sakamoto type III (inferior vena cava tumor thrombus reaching the right atrium) cannot be enrolled. * Subjects with oligometastases outside the liver can be enrolled: Oligometastases outside the liver are defined as up to three metastatic lesions in a maximum of two organs, with the largest diameter being 3cm. * Child-Pugh score less than or equal to 7. * Adequate organ and bone marrow function, with laboratory test values meeting the following requirements within 7 days prior to inclusion (no blood components, cell growth factors, albumin, or other intravenous or subcutaneous corrective treatment drugs are allowed within 14 days prior to obtaining laboratory tests): 1. Complete blood count: Absolute Neutrophil Count (ANC) ≥1.5×10\^9/L; Platelet count (PLT) ≥75×10\^9/L; Hemoglobin (HGB) ≥9.0 g/dL. 2. Liver function: Total Bilirubin (TBIL) ≤2×Upper Limit of Normal Value (ULN); Alanine Aminotransferase (ALT) and Aspartate Transferase (AST) ≤5×ULN; Serum albumin ≥28 g/L; Alkaline Phosphatase (ALP) ≤5×ULN. 3. Kidney function: Serum Creatinine (Cr) ≤ 1.5×ULN or Clearance of Creatinine (CCr) ≥50mL/min (Cockcroft-Gault formula); Urinalysis shows proteinuria \<2+; For subjects with baseline urinalysis showing proteinuria ≥2+, a 24-hour urine collection should be performed and 24-hour urinary protein quantification \<1g. 4. Coagulation function: International Normalized Ratio (INR) ≤2.3 or Prothrombin Time (PT) extension ≤6 seconds. * Estimated life expectancy of ≥12 weeks. * Female subjects of childbearing age or male subjects whose sexual partners are of childbearing age need to take effective contraceptive measures during the entire treatment period and for 6 months after the last medication. * Signed written informed consent, and able to comply with the visit and related procedures stipulated in the protocol. Exclusion Criteria: * Histologically/cytologically confirmed sarcomatoid intrahepatic cholangiocarcinoma, mixed hepatocellular carcinoma, etc. * History of hepatic encephalopathy or liver transplantation. * Clinically symptomatic pleural effusion, ascites, or pericardial effusion requiring drainage. Patients with only radiologically detected minimal pleural effusion, ascites, or pericardial effusion without symptoms can be included. * Acute or chronic active hepatitis B or C infection, with hepatitis B virus (HBV) DNA \>2000IU/ml or 10\^4 copies/ml; hepatitis C virus (HCV) RNA \>10\^3 copies/ml; co-positive for hepatitis B surface antigen (HbsAg) and anti-HCV antibody. Patients who meet the above criteria after antiviral treatment with nucleoside analogs can be included. * Presence of central nervous system metastases. * History of esophageal or gastric variceal bleeding due to portal hypertension within the past 6 months. Patients assessed by the investigator to be at high risk of bleeding. * Any life-threatening bleeding event within the past 3 months, including those requiring blood transfusion, surgery or local treatment, or continuous drug treatment. * History of arterial or venous thromboembolic events within the past 6 months, including myocardial infarction, unstable angina, cerebrovascular accident or transient ischemic attack, pulmonary embolism, deep vein thrombosis, or any other serious thromboembolic events. Exceptions are made for thrombosis formation related to implanted venous infusion ports or catheters, or superficial vein thrombosis that has stabilized after routine anticoagulation treatment. Preventive use of low-dose low molecular weight heparin (such as enoxaparin 40 mg/day) is allowed. * Continuous use of aspirin (\>325 mg/day) or other known platelet function inhibitors such as clopidogrel or ticlopidine for 10 days within 2 weeks prior to the first dose. * Uncontrolled hypertension, with systolic blood pressure ≥150mmHg or diastolic blood pressure ≥100mmHg after optimal medical treatment, history of hypertensive crisis or hypertensive encephalopathy. * Presence of any toxicity caused by previous treatment that has not recovered to grade 0 or 1 according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0 (NCI CTCAE 5.0) before the first dose of study treatment (excluding alopecia, non-clinically significant and asymptomatic laboratory abnormalities). * Symptomatic congestive heart failure (New York Heart Association class II-IV), left ventricular ejection fraction (LVEF) \<50% as indicated by echocardiography. * Symptomatic or poorly controlled arrhyth